Look at the original quote: "Oop, Katie's got the low cut dress on today! I know where I'm sitting!" A clear statement of sexual interest, which Katie clearly did not wish to receive.
The hypothesis we are being asked to entertain is that she probably was wearing the low-cut dress because she wanted to attract male attention, but that this comment was in some other way offensive. That is, she wanted this guy to think that, just not say it. Because women are touchy, or something. What an absurdly insulting proposal!
Is it really so hard to imagine that she might want to dress in a way which is gratifying to her, without intending to be the object of men's sexual fantasies?